Opposites Collide
by LaynaPanda
Summary: If an Angel and a Demon were to fall in love with each other, can their love transcend the law of Heaven and Hell? Can the Angel set her wings on fire? Can the Demon soar at day light? Love can't change what aren't meant to be. The same goes for the Angel Lucy and the Demon Natsu. —NatsuxLucy
1. Chapter 1

**a/n: **yes, so I saw this fanfiction that was made by _**purplekittyfans465**_ and obviously, I wouldn't re-write it if I didn't love the plot so you should totally go check that out because it's the original one. Mine will be completely different but I am using the same plot so why not? I hope you guys enjoy. (:

I can't really update a lot anymore—I have lacrosse.

* * *

"Lucy Heartfillia... my dear angel of a daughter, will infiltrate the underworld disguised as a demon to kill the demon, Natsu Dragneel. He has caused too much trouble and he _has_ to be killed or else... the world might actually break apart. Please, do your best to kill him... the world is depending on you, Angel."

"Pah! What kind of request is that? I don't even know how he looks like and this place is all so creepy... why am I even here?! Why couldn't anyone else do it?! I'm not the only one with dark powers too!" Lucy muttered under her breath as she walked through the hallway of the dark school that taught dark magic and how to control powers. There were spirits and demons everywhere and most of them look very scary to her... she was lucky she was given clothes to fit in... If not, she would have probably been killed the moment she stepped into the underworld.

This place was freaking her out and she was about to scream in fury when someone bumped into her, making her body slam against the wall.

Lucy groaned and turned around to notice it was a demon with horns sticking out of his oddly pink hair, red dragon-like wings coming out of his back, his teeth sharper than normal and a wide grin on his face. He looked worried when he noticed she looked a bit pained. "Are you okay?"

"Watch where you're going next time—I could have seriously gone hurt."

"Sorry, I wasn't looking. You're that new chick who's in my assassin class, right?"

"My name is Lucy, not 'that new chick' okay?"

"Lucy," he said, testing the new name out as it rolled off his tongue. He was silent for a moment before he eyes flashed, smiling at her warmly. "Hi, I'm Natsu Dragneel."

_It's him!_

"I hope we can be friends." He said making Lucy nod and watch him walk away with his other demon friends, making her watch his disappearing figure. The guy didn't look so bad and he was actually pretty polite... why did they want him captured in the first place?

He did appear a bit reckless... maybe he was a pyromaniac?

Either way—Lucy vowed she will not failed this mission; this was an important one after all.

* * *

The next couple of days, Lucy followed the so-called Natsu demon around and from what she saw—he didn't look like a bad guy.

He was polite in some ways and he was that typical 'mess-with-me-and-I'll-hurt-you' kind of person. He had friends and he would laugh and such, from what Lucy saw, he was a nice young demon that was originally targeted by the gods for _some_ reason. If she was god... she would spare this handsome demon.

Well, that was what she thought until she witnessed him blowing up a classroom with his reckless magic that supposedly, burned something down until it became full on ashes and rubble.

His magic—fire god slaying.

No wonder the gods wanted him—he was a god slayer which was a forbidden dark magic that only the demons long ago used. Nobody knew how he got it and he said his father, the Devil, taught him personally but nobody had ever seen the Devil before so they all thought they were bluffing. But Lucy didn't, she personally knows the Devil since her father, the God, used to be close with him until he all turned wacky.

She still needed to capture him but she felt the urge not to.

* * *

The week after she had entered the underworld, she was actually enjoying her time there.

She made friends and learned a lot of things and the most important thing of all... she had befriended the demon she was supposed to kill. Sure, it was a bad idea but she needed to learn things to know _why_ he was supposed to be killed and such. He didn't seem like a bad person but what if he was the worst? This was only because of the mission, of course.

And of course she's going over to his house later to know more about him.

And of course she's just holding hands and hugging him for the mission.

And yes... of course she's slowly starting to like him... _for the mission._

* * *

The next month was when she wanted to go back to heaven and make her father choose another person for the job. The reason behind it was because... she fell for the stupid demon.

Yes, she fell for the idiotic stupid demon that bothers her during class, makes fun of her, laughs with her, and made her heart go _thump-thump_.

How could an Angel like her fall for a Demon like him? It was surely impossible and forbidden from the last time she checked and when her father knows about this... there will be a war happening between the underworld and Heaven.

She knew she promised she'll fulfill this mission but she knew it was impossible since she practically _fell_ for the demon... how can she watch her crush get slaughtered and get captured by her father? It was worse than falling in love... she was surely going to die with him once she sees that! But... she can't let love get in the way... she vowed and Angel's never break promises.

—**X**—

"Hey, Natsu? Can I speak with you, privately?"

"Huh? Yeah, sure thing Luce." The demon replied as he finished writing whatever he was writing before the two left the classroom to the outdoors. Lucy nervously chewed on her bottom lip as her palms became sweaty and her heart raced.

She was going to do it—she was going to tell him and capture him and bring him back up. She was going to do it and her heart couldn't tell her otherwise.

Once they were outside and far away from ear-shot distance, she turned and looked at the male who grinned at her, making her heart skip a beat. She gasped and looked at him worryingly before looking away, whining about how she couldn't do this anymore.

"Luce, you okay there?"

"Natsu—do you like somebody?!" Lucy asked quickly as she stared at the demon who looked quiet shocked. He rubbed the back of his head and shrugged. "I mean... demons don't really have feelings."

"I _know_ that but if you learn to develop them—you have them."

"I know." He replied, nodding as if he knew. "I know because I do have them."

"You have what?"

"Feelings. I have feelings. I learned to get them when... uh, you came actually."

"What?" Lucy asked, a bit surprised he was so blunt about it. Then again, he was a demon with no secrets and no emotions at all.

"I think I fell for you." He said once again, shrugging his shoulders. He looked at her as their eyes locked and he gave her a sad weak smile, trying his best not to show any other emotion. "But... that's impossible for us, right?"

"I—impossible? Why is it impossi—"

"Because you're an Angel."

Lucy felt the air get sucked out of her lungs as she heard what he said, her brown eyes widened as she took a step back to bump into the wall that was behind her. She stared at him with shock filling her body as her hand rose to her mouth, looking at him to shrug casually once more. "I know you are one but don't worry... nobody else knows but me."

"H—how..? How'd you know? I'm—"

"Luce, there's _no_ way you're a demon." He scoffed, letting out a soft laugh as he imagined her as a demon. "You're the total opposite as one. You're actually really nice and sweet and trust me; anyone could see that glow coming from you."

"But—didn't you say nobody else knew?!"

"Yeah, but Luce, it's not like it's really noticeable. You need to be close and you know... we're close." He said as he looked away a bit bashfully. He cleared his throat and smiled a bit, remembering the good times he had with her. "I don't know why an Angel is here in the underworld though... are you possibly fulfilling a mission?"

Lucy become silent and still as she gulped down the bile that threatened to rise upwards.

She couldn't possibly tell him this... no way, no how. He'll hate her—he'll try to kill her even though their friends and anyone that would try and kill you, of course they'll fight back. And demons could be way stronger than Angel at some points... Lucy had no chance. But it was better... far from worse if she had to kill him herself.

"I understand you'll hate me after this but... I'm here to... kill you."

"What?"

"I'm supposed to kill you." Lucy said once again, her body trembling a bit. "I know that's a bad thing and I know you don't want to die yet but I don't want that either! The past months I've been in the underworld have been a blast, actually! I met you and I fell for you and now I can't do that stupid mission I promised I'll do because I fell for the person I'm supposed to bring back to heaven to kill! Why was it you?! Why?!" Lucy cried out as she started to pound on his chest, tears rushing down her face as Natsu watched her cry and scream, standing in his original spot as she hit him over and over again.

Lucy leaned against the man who just silent watched her, waiting for his reply. "You can kill me right now... I wouldn't mind... I'm just happy that I met someone like you..."

"Marry me."

"And I know I'm the one suppose to kill you but—wait, what?"

"Luce, marry me. Marry me and we can have half demon half angel babies and we can be the couple of the entire era. Fuck that mission—marry me and I promise I'll do whatever I can to make you happy." Natsu said as he reached forward and clutched her hands in his, staring right into her eyes as she blinked back tears, staring at him as if he was crazy.

"Didn't you hear what I just said?!"

"Yes but I don't care... I love you."

"You love me enough to break the rules and marry an angel?!"

"Yes." Natsu said with full honestly making Lucy's heart flutter.

Tears brimmed in the corners of her eyes as she launched herself into her arms, transforming herself back to her glowing angel self as she shined and glowed, her wings and halo appearing as her outfit changed completely. Her horns and wings faded away and she became the beautiful angel she was, making Natsu smile and embrace her. "For you, I would gladly break the law any day."

"But it's forbidden?"

Suddenly, Natsu scoffed as he kissed her temple, a smirk appearing on his handsome face. "Who said I followed the rules anyways?"

* * *

**a/n: **tbh it didn't turn out the way I wanted... it's crapper and I knew I should have not written it. It could have been written better but eh... I'm tired enough. I hope you enjoyed this /crappy/ version of _Opposites Collide! _

Don't forget to leave a lovely review!~


	2. Chapter 2

**notes: **so I saw something that made my heart pound and my mind think of this story which is why I wrote another chapter to this but instead of it continuing the first chapter, it's going to be **_completely different_**. As in, it won't continue off the first chapter but instead, its going to be like a new series of it. but I don't think there's going to be a new one after this one... we'll have to see.

**notes2: **happy new year x

* * *

"You're fucking stupid, Natsu. You're going to get yourself killed up there!" Gray, his close demon friend, yelled as the male prepared to leave. "A lot of demons die up there! It's impossible for you!"

"Will you shut up already?" The male hissed as he whipped his head around to shoot a dirty look towards the male. "I'm going to go hunt down this human and bring her back with me and prove you wrong," the male said as he wandered off somewhere making Gray follow. "besides, I've got nothing better to do."

"Angels roam the earth all the time. They'll easily find you. You'll die."

"I just won't do anything bad. then."

"You sure you can find this girl in a month before your protection wears out?"

"Hey," he smirked. "if I don't return in a month, you know I've died."

Punching the male's shoulder, Gray glared at his friend who only sniggered. "You're fucking stupid."

"Yeah, yeah," the pink-haired demon rolled his eyes as he threw a toothy smirk his way, saluting him with two fingers. "see you in a month, headass."

—**X**—

When Natsu arrived to the world full of humans and other sorts of junk he learned about back in the underworld, he had to admit, he wasn't as impressed. The world was dirty and there were loads of humans where it just made him utterly uncomfortable. And a few Angels who just threw him warning looks and a couple of other mythical creatures that hid away from the humans roamed around as well, making him blend in quiet well. But the only thing that could make him a bit different from the humans would be his abnormal body heat and his slightly sharper teeth.

Other than that, he was completely human disguised. And a young one, too.

"Damn, I look good." Natsu murmured to himself as he looked at his reflection from a store window, smirking in a cocky way. "Must be nice to be so good-lookingin this world."

Turning around to start his little mission, he immediately bumped into somebody and he quickly pulled away, expecting some sort of burning sensation but experiencing nothing.

"Shit, I'm sorry—"he apologized as he noticed a human woman on the ground in front of him. "here, let me help you." He offered as he reached forward and helped her up, the blonde stumbling against him as she barely had the time to react.

Natsu watched in pure amusement and interest as he realized she didn't make his skin burn with the way it would when a human would touch him.

Maybe this woman was—?

"I'm very sorry, I bumped into you without looking." The blonde apologized sheepishly, offering a shy smile. "I hope you're okay?"

"You're the one who fell," he smiles back. "I should be the one apologizing and asking if you're okay."

"I'm fine, really." She laughed slightly before her smile fell and a gasp flew out of her mouth. "My meeting—! Uh, it was nice meeting you! I have to run, have a great day!" She shouted before running off in the opposite direction he was facing making him turn and watch her disappear into the sea of people.

Natsu couldn't help but think that woman was slightly odd. Just the way she acted and how she didn't burn him.

He realized that he found the woman he has been looking for.

—**X**—

"Perks of being special," Natsu happily sang as he twirled the keys around on his finger. He walked down the corridor to his new apartment which was right next to the woman he saw earlier today, a large grin on his face. "can't wait to prove that dick Gray wrong. I already found her and it's only been three hours." He smirked while grabbing his use key to unlock his new apartment.

Once he entered, he was welcomed with the vacant area of his new apartment and the fresh smell of home.

"Now, what am I going to do till she—"

As if it was on cue, he heard the door open next door and the click of the heels on the wooden floor. His sensitive ears heard everything and his nose tingled as he smelt the sweet aroma of her scent.

He felt the same smug smirk crawl up his mouth and he prepared himself to go introduce himself.

"This is so much easier than I thought it would be..." he chuckled to himself as he left his vacant apartment to go next door to ask for a cup of sugar or something.

Now to put his acting skills into place. His father would be so proud.

Brushing his knuckles against the wooden door, Natsu's eyes widen when he watched the wooden slightly burn making him curse and hide his hands behind his back. Just then, the door opened and the same woman he saw earlier stood in front of him except with her hair down and everywhere from her bun she had and her blouse unbuttoned.

Natsu felt like he was at daze as he stared at the beauty in front of him.

She looked almost like an Angel but he hated Angels and he was almost certain she wasn't one. She was human... somebody special, someone who he had to hunt down and bring to his father dead or alive.

But she looked so... _beautiful_.

"Oh! You're that man from earlier today!"

Snapping out of his trance, he offered a smile. "Hey, you're the woman from earlier. I didn't know you lived here! I was just wondering if you had some sugar or something 'cause I'm about to make something," he jabbed his finger towards his apartment making her lean forward and look down the hall.

"What? You live next door to me, now? Wow, that is pure coincidence!" She giggles cutely making his insides all warm. "Sure thing! I was actually just about to order some take-out. Why don't you join me?"

"Are you sure? I mean, I don't want to bother you."

_I just need to kill you._

"Oh no! I would love some company and you are my neighbor, now." She stuck her hand out. "I'm Lucy. Lucy Heartfillia." She offered a wide smile making him cautiously reach forward and grasp her small hand in his. He eyes their connected hands and waited for some kind of reaction but never got anything making him smile in return.

"My names Natsu... Natsu Dragneel."

"Well Natsu, I hope you like Chinese and stupid cartoons because that's what's on the agenda tonight."

"Are you kidding me? I love Chinese and cartoons!"

* * *

"You're surprisingly a good cook."

"What is that supposed to mean?" The blonde threw him a playful glare as she held a pot in her hand, the other one holding onto a large spoon. She looked almost like a wife cooking for the husband while Natsu sat at the dinner table, test-tasting the food. "I am a great cook, thank you."

"Yeah, I know," he leaned against his palm, waiting for the woman in the apron to come on over. "I just didn't think you would cook."

"And why do you say that?"

"I don't know, you don't look like the type to know how to cook."

"What do I look like then?"

"I don't know," he offered a smile as he watched the blonde scoff and turn her back towards him. His hand twitched against the cool bottle he had in his pocket as he remembered his mission. He squeezed it absentmindedly and pressed his lips into a tight line, watching the back of the woman.

He should be putting the poison in her food and he should have already returned to the underworld with her. He shouldn't be spending time with the blonde more than he should without fulfilling his duty. He didn't know what was going on anymore.

She made her way into his dark heart somehow and he hated it.

He wanted to throw a tantrum. He wanted to kill her. He didn't want this, he shouldn't be feeling anything towards this woman but pure hatred but why was he hesitating?

_Why_?

Slowly pulling the bottle of poison out of his pocket, he was stopped midway when he heard the voice of Lucy.

"Hey Natsu, guess what I made?"

"Uh, meatloaf 'cause that's what's in front of me—"

"No." the blonde laughed as she turned around to throw him a smile. "I made brownies!" She presented the pan full of fresh hot brownies making his mouth water. "I remember you telling me you really likes brownies so I made a fresh batch! We can have some after dinner."

Shoving the bottle back in his pocket, the male couldn't help but grin widely and forget about the entire mission.

"Wow, you're the best, Luce!"

"I know," she smirked, placing the pan on her counter to allow it to cool. "you can thank me later."

Looking up, Natsu wiggled his eyebrows in her direction making her flush and cry out.

"Not like that you pervert!"

* * *

"You know what I really think about?"

"What?"

"What happens when you die."

This caught the demon's attention as his head turned and his obsidian orbs locked with the chocolate ones that belonged to the woman next to him. The two were sprawled out on the floor of her apartment, fluffy pink carpet tickling their skins. They were so close they almost touched but the only things that were touching were their hairs.

After finishing a marathon of _The Big Bang Theory_ and eating almost all the junk food she had in her home, the two were beat and the sun already went to sleep.

"Like, I want to know what happens when you die. Is there heaven or hell?"

"Yeah," he answered back without thinking. It caught Lucy's attention making his gaze fall somewhere else. "I mean, like, I believe in that. That were a few people who witnessed heaven or hell or seen demons or Angels so yeah, I believe it." He quickly said making her scoff and smile slightly, looking back at her ceiling.

"You believe their words? What if they're lying?"

"And how do you know if they're not?"

Looking over at the male once more, their eyes locked and that was all they needed before they laughed out loud, both of them inching closer to each other.

"Y'know, you're really warm..."

"Yeah, I was born with it."

"And you have such sharp teeth."

"Runs in the family."

"And you also have pink hair..."

"Tell me something I don't know," he scoffed, rolling his eyes as the corners of his mouth twitched up to a smile.

The couple gazed at each other in silence as Lucy leaned in against his ear. "I know what you are." She whispered into his ear making his smile drop and his eyes widen slightly. "You're something that doesn't belong in this world... you're not apart of this world."

Swallowing thickly, Natsu felt his palms grow sweaty as the hot breath of the blonde tickled his neck.

"You're exactly what they say about in the books..."

"What am I, Lucy? Tell me, what are you going to do?"

"What are you?" She laughed against his ear making a shiver run down. "You're... you're a werewolf."

"That's right, I'm a—_wait_, did you just call me a fucking _werewolf?_" Natsu leaned back to look at the woman who suddenly burst into fits of giggles making the rosy-haired demon stare. "Lucy, what the actual fuck."

"It's okay," she giggled, placing a hand on his shoulder. "I was always apart of team Jacob."

Natsu could only stare at the woman as if she was the craziest person out there, seriously debating weather or not if he should just kill her there and now.

"You're so dumb," he sighed making her giggle again and snuggle herself into his arms. "why am I friends with you?"

"I don't know, you came to me." She grinned making him sigh and close his eyes. His used his other hand to cover his forehead, wondering where he went wrong.

But soon, he was shaking with laughter as well.

* * *

"Lucy, I've gotta talk to you."

"Hold up," she raised her finger to his face as the woman continues to speak into her cellphone, a bright smile on her face.

"Lucy," he spoke again, coming in front of her to have her turn away and put her finger up to his face again making him annoyed. "Luce."

"Natsu, can't you see I'm on the phone?" She practically hissed before she place the phone against her ear again, apologizing towards the person on the other side. "Sorry, my friend is over and he's kind of being—_hey_! Natsu, what's the big idea?" Lucy cried out when he snatched the phone away, the look of pure anger and annoyance stretched across his face. "Natsu—!"

Gripping onto the phone tighter, her cellphone suddenly started to melt and shatter making her gasp, her eyes widening as she took a step back.

"Na—Natsu?"

"I have something to say," he said, his voice deep and husky making her slightly nervous all of a sudden. "and it's important."

Unable to say anything, she quickly nodded her head making him take in a deep breath and sigh.

"Lucy, almost a month ago, I was brought into this world by my father. I was assigned a mission, a mission to find a special human and bring her back to the underworld dead or alive." He fanned his hot breath against her face making her stare up at him with wide glossy eyes. "That human is you. You have something in you, Lucy. Something that repels any sort of dark magic even though you're human. And we need you." He reached forward making her flinch and squeeze her eyes shut.

It made him frown and hesitate slightly but he brushed his hand against her face, forcing her to open her eyes again.

"I'm a demon, Lucy. I destroy almost everything I touch..." He reached around to grab the closest thing near them making it slowly burn away in his hands. "all except you."

"How... why... why haven't I seen this earlier? Why didn't it happen before?"

"Lotion," he chuckled slightly as he reached forward to cup her face and hold her. "but you... I don't need to do anything. You don't perish in my hands."

"Why... Natsu... why—"

"My father..." he spoke again, his dark eyes boring into hers. "he made me come here to capture you and if I don't come back within a month, I die in this world. But you wanna know something funny?" His laugh was bitter. "I felt something. _I felt something_. I'm a fucking demon, we don't_ feel anything._ We don't have feelings, especially for _humans_." He ran his hand through his hair and face making her stare at the handsome male in front of her. "I'm feeling something and it has something to do with _you._" He almost cried making Lucy swallow thickly, her heart thumping harder and faster than normal. "I almost hate you for making me feel this way."

"Natsu—"

"But I rather die then kill you."

"Natsu I—"

"So I'm not going to kill you and rather sacrifice myself—"

"Natsu!" The blonde shouted, catching the attention of the demon. "I don't care about your mission or anything else... I'm not scared of you because I know a different side of you than this disastrous demon you." She gestured towards the destroyed material on her ground. "But what I do care about... is you." She leaned in to brush her lips against his slightly making his breath hitch. "I never thought I'll say this to a demon but I love you."

"What? You rather say it to an angel?"

"Nah," she smiles cutely, wrapping her arms around his broad shoulders. "because demons are way cooler. I was always _Team Demon _anyways," she snickered before she leaned into press her lips against his making him growl from the back of his throat. His strong arms wrapped around her small figure and brought her closer, his lips pressed against hers even tighter.

Pushing the woman back against the wall, his hand rubbed against her back as she gripped into his biceps.

He pulled away and hovered his lips above her swollen ones, his eyes hooded as he stared down at the blonde. "I've already been to hell, sweetheart. Show me what heaven is like." He nibbled on her bottom lip as his fingertips ran up the inside of her thighs.

Lucy merely sighed before she brought him even closer to kiss him once again.

"With pleasure."

* * *

—**X**—

* * *

The first day of the next month, Lucy sat in her apartment staring at her novel when she suddenly heard the door open and somebody enter. This caught her by surprised since she wasn't expecting anybody and Natsu already left but... who was in her home?

A burglar? Was this person here to kill her?

Standing up to get ready to make a dash for it, the woman whirled around to see who it was when suddenly she felt a pair of arms snake around her waist and a palm cover her mouth before she had the chance to scream.

Her eyes were wide as she was met with dark ones, amusement dancing in the eyes of her guest.

"Nasu?!"

"Hey baby," his hot breath brushed against her face. "missed me?"

Pulling his hand away from her mouth, Lucy let out a gasp. "What—what are you doing here? Didn't you—weren't you—?!"

"Die? Yeah, weird, right?" Natsu guffaws loudly making her furrow her brows and look at the male in front of her. "Looks like, when we, uh, when you and I," he flushed slightly making her flush as well. "yeah, well, apparently when we did it, you kind of, uh, made me mortal."

"What?" She practically shrieked making him grin. "Is that even possible?"

"Guess so."

"How did you—how did you know? What is gong to happen?"

"I really don't know but yesterday when I was preparing to leave or die, I was reading the spell book and I gave myself a paper cut and I bled. I started_ bleeding, _Lucy, look!" He his finger up to show the bandaged finger. "Demons don't bleed! Only humans do! I became human, I'm can stay here, with you!"

"Oh darn, I thought I finally got rid of you last night." Lucy swung her arm on defeat as she sighed making Natsu gawk. The blonde noticed how hurt the male looked and she started to laugh, cupping his face to bring him close. "I'm kidding. I'm so happy!"

"Or are you?" He questioned, his eyebrow raised as he stared at the female in front of him who rolled her eyes. "Just kidding." He leaned in to press a chaste kiss against her lips.

Smiling against the lips of the male, Lucy only sighed.

"Guess opposites do attract."

* * *

**notes**: I'm sorry this turned out more crappy and rushed than it was supposed to be.

**notes2**: happy new year! I hope you all had a great New Years! did anyone start school, yet? I did yesterday but it snowed today giving me a day off!

**notes3**: leave me a review if demon natsu made you weak in the knees


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